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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 901 records · Page 50Linked to original sources
PubMed1977

Laboratory utilization in group general practice.

A survey was made of laboratory utilization in a busy group general practice for a one-month period. Approximately 10% of all patients seen in the period were referred for laboratory investigations. The majority of patients were females. Data are presented on abnormal results, laboratory area utilization and report time expectations. The pilot study suggests that there is a demand for local laboratory services in practices where four or more doctors are practicing, but other factors involved require investigation and assessment.

Australia↗
PubMed1977

Fetal cerebral oxygen consumption at different levels of oxygenation.

Cerebral oxygen consumption (VCO2) was measured in 10 unanesthetized, chronically catheterized fetal sheep at 130-140 days of gestation. The VCO2 was calculated using cerebral blood flow (QC) measured with radioactive microspheres and the cerebral arteriovenous difference of O2 content (C(a-V)O2) calculated from preductal arterial and sagittal sinus venous blood. The ewe was exposed to varying concentrations of oxygen, resulting in fetal arterial oxygen contents (CaO2) of 0.89-5.58 mM, arterial oxygen tension (PaO2) values of 14-36 Torr, and cerebral venous oxygen tension (PVO2) values of 9-25 Torr. Although there was a clear relationship between the fetal CaO2 and C(a-V)O2, this was shown to be the result of changes in Qc rather than changes in VCO2. There was not a statistically significant correlation between either CaO2 or PVO2 and VCO2 over this range of oxygenation. On the other hand, C(a-V)O2 was highly correlated with Qc. There is no evidence that VCO2 is a function of oxygen tension (PO2) in the unanesthetized fetal sheep as long as the sagittal sinus PO2 is greater than or equal to 9 Torr.

Animals↗
PubMed1977

A simple method for ECG and VCG assessment of the severity of pulmonary valve stenosis.

In patients with isolated pulmonary valve stenosis, the right ventricular (RV) hypertrophy is related to the hemodynamic severity of their lesions. We estimated the peak RV pressure noninvasively in 112 patients with isolated pulmonary valve stenosis by a Frank lead vectorcardiogram (VCG), an orthogonal electrocardiogram (ECG), and a standard scalar ECG. In 78 randomly assigned patients, 10 ECG measurements and 13 VCG measurements were correlated with the peak RV pressure at cardiac catheterization; the best multiple linear regression equation used the R wave in standard lead 1 (ECG), maximal rightward voltage in the terminal part of the frontal vector loop (VCG), and the Q wave in the orthogonal Z lead, giving R = 0.66 (SEM 25). The equation was validated in the other 34 patients; correlation of estimated with actual peak RV pressure was r = 0.64. A nomogram for clinical use was devised from this regression equation.

Adolescent↗